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Y-station
The "Y" service was a network of British signals intelligence collection sites, the Y-stations. The service was established during the First World War and used again during the Second World War. The sites were operated by a range of agencies including the Army, Navy and RAF plus the Foreign Office (MI6 and MI5), General Post Office and Marconi Company receiving stations ashore and afloat. There were more than 600 receiving sets in use at Y-stations during the Second World War. Background The "Y" stations tended to be of two types, for intercepting of the signals and for identifying where they were coming from. Sometimes both functions were operated at the same site, with the direction finding (D/F) hut being a few hundred metres from the main interception building, because of the need to minimise interference. The sites collected radio traffic which was then either analysed locally or if encrypted, passed for processing initially to the Admiralty Room 40 in London and during Worl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signals Intelligence
Signals intelligence (SIGINT) is intelligence-gathering by interception of ''signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly used in communication (electronic intelligence—abbreviated to ELINT). Signals intelligence is a subset of intelligence collection management. As classified and sensitive information is usually encrypted, signals intelligence in turn involves the use of cryptanalysis to decipher the messages. Traffic analysis—the study of who is signaling whom and in what quantity—is also used to integrate information again. History Origins Electronic interceptions appeared as early as 1900, during the Boer War of 1899–1902. The British Royal Navy had installed wireless sets produced by Marconi on board their ships in the late 1890s, and the British Army used some limited wireless signalling. The Boers captured some wireless sets and used them to make vital transmis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bletchley Park
Bletchley Park is an English country house and estate in Bletchley, Milton Keynes ( Buckinghamshire) that became the principal centre of Allied code-breaking during the Second World War. The mansion was constructed during the years following 1883 for the financier and politician Sir Herbert Leon in the Victorian Gothic, Tudor, and Dutch Baroque styles, on the site of older buildings of the same name. During World War II, the estate housed the Government Code and Cypher School (GC&CS), which regularly penetrated the secret communications of the Axis Powersmost importantly the German Enigma and Lorenz ciphers. The GC&CS team of codebreakers included Alan Turing, Gordon Welchman, Hugh Alexander, Bill Tutte, and Stuart Milner-Barry. The nature of the work at Bletchley remained secret until many years after the war. According to the official historian of British Intelligence, the "Ultra" intelligence produced at Bletchley shortened the war by two to four years, and without it th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wireless Experimental Centre
The Wireless Experimental Centre (WEC) was one of two overseas outposts of Station X, Bletchley Park, the British signals analysis centre during World War II. The other outpost was the Far East Combined Bureau. Codebreakers Wilfred Noyce and Maurice Allen broke the Japanese Army's Water Transport Code here in 1943, the first high-level Japanese Army code broken. John Tiltman broke prewar Russian and Japanese codes at Simla and Abbottabad. Location and function The WEC was located in Ramjas College (formerly part of the Delhi University campus), atop a hill called Anand Parbat "the hill of happiness" and was several miles out of Delhi and hence secure. Staff were from the Intelligence Corps, the British and Indian armies and the Royal Air Force. Section C under Colonel Marr-Johnson was a radio (wireless) intercept station and decoding section for Japanese codes. There were three outstations: the Wireless Experimental Depot in Abbottabad (where Russian (Soviet) transmissions were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chipping Barnet
Chipping Barnet or High Barnet is a suburban market town in north London, forming part of the London Borough of Barnet, England. It is a suburban development built around a 12th-century settlement, and is located north-northwest of Charing Cross, east from Borehamwood, west from Enfield and south from Potters Bar. Its population, including its localities East Barnet, New Barnet, Hadley Wood, Monken Hadley, Cockfosters and Arkley, was 47,359 in 2011. Its name is very often abbreviated to just Barnet, which is also the name of the borough of which it forms a part; the town has been part of Greater London since 1965 after the abolition of Barnet Urban District then in Hertfordshire. Chipping Barnet is also the name of the Parliamentary constituency covering the local area – the word "Chipping" denotes the presence of a market, one that was established here at the end of the 12th century and persists to this day. Chipping Barnet is one of the highest urban settlements in Lond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adcock Antenna
The Adcock antenna is an antenna array consisting of four equidistant vertical elements which can be used to transmit or receive directional radio waves. The Adcock array was invented and patented by British engineer Frank Adcock in 1919 as British Patent No. 130,490, and has been used for a variety of applications, both civilian and military, ever since. (Note: The patent lawyer's name appears as inventor, with "F. Adcock" in parentheses, since Lt. Adcock, RE was serving in wartime France at the time.) Although originally conceived for receiving low frequency (LF) waves, it has also been used for transmitting, and has since been adapted for use at much higher frequencies, up to ultra high frequency (UHF). In the early 1930s, the Adcock antenna (transmitting in the LF/MF bands) became a key feature of the newly created radio navigation system for aviation. The low frequency radio range (LFR) network, which consisted of hundreds of Adcock antenna arrays, defined the airways use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allies In World War II
The Allies, formally referred to as the United Nations from 1942, were an international military coalition formed during the Second World War (1939–1945) to oppose the Axis powers, led by Nazi Germany, Imperial Japan, and Fascist Italy. Its principal members by 1941 were the United Kingdom, United States, Soviet Union, and China. Membership in the Allies varied during the course of the war. When the conflict broke out on 1 September 1939, the Allied coalition consisted of the United Kingdom, France, and Poland, as well as their respective dependencies, such as British India. They were soon joined by the independent dominions of the British Commonwealth: Canada, Australia, New Zealand and South Africa. Consequently, the initial alliance resembled that of the First World War. As Axis forces began invading northern Europe and the Balkans, the Allies added the Netherlands, Belgium, Norway, Greece, and Yugoslavia. The Soviet Union, which initially had a nonaggression pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Admiral Dönitz
Admiral is one of the highest ranks in some navies. In the Commonwealth nations and the United States, a "full" admiral is equivalent to a "full" general in the army or the air force, and is above vice admiral and below admiral of the fleet, or fleet admiral. Etymology The word in Middle English comes from Anglo-French , "commander", from Medieval Latin , . These evolved from the Arabic () – (), “king, prince, chief, leader, nobleman, lord, a governor, commander, or person who rules over a number of people,” and (), the Arabic article answering to “the.” In Arabic, admiral is also represented as (), where () means the sea. The 1818 edition of Samuel Johnson's ''A Dictionary of the English Language'', edited and revised by the Rev. Henry John Todd, states that the term “has been traced to the Arab. emir or amir, lord or commander, and the Gr. , the sea, q. d. ''prince of the sea''. The word is written both with and without the d, in other languages, as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
U-boats
U-boats were naval submarines operated by Germany, particularly in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic warfare role (commerce raiding) and enforcing a naval blockade against enemy shipping. The primary targets of the U-boat campaigns in both wars were the merchant convoys bringing supplies from Canada and other parts of the British Empire, and from the United States, to the United Kingdom and (during the Second World War) to the Soviet Union and the Allied territories in the Mediterranean. German submarines also destroyed Brazilian merchant ships during World War II, causing Brazil to declare war on both Germany and Italy on 22 August 1942. The term is an anglicised version of the German word ''U-Boot'' , a shortening of ''Unterseeboot'' ('under-sea-boat'), though the German term refers to any submarine. Austro-Hungarian Navy submarines were also k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of The Atlantic
The Battle of the Atlantic, the longest continuous military campaign in World War II, ran from 1939 to the defeat of Nazi Germany in 1945, covering a major part of the naval history of World War II. At its core was the Allied naval blockade of Germany, announced the day after the declaration of war, and Germany's subsequent counter-blockade. The campaign peaked from mid-1940 through to the end of 1943. The Battle of the Atlantic pitted U-boats and other warships of the German '' Kriegsmarine'' (Navy) and aircraft of the ''Luftwaffe'' (Air Force) against the Royal Navy, Royal Canadian Navy, United States Navy, and Allied merchant shipping. Convoys, coming mainly from North America and predominantly going to the United Kingdom and the Soviet Union, were protected for the most part by the British and Canadian navies and air forces. These forces were aided by ships and aircraft of the United States beginning September 13, 1941. Carney, Robert B., Admiral, USN. "Comment and Discu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-frequency Direction Finding
High-frequency direction finding, usually known by its abbreviation HF/DF or nickname huff-duff, is a type of radio direction finder (RDF) introduced in World War II. High frequency (HF) refers to a radio band that can effectively communicate over long distances; for example, between U-boats and their land-based headquarters. HF/DF was primarily used to catch enemy radios while they transmitted, although it was also used to locate friendly aircraft as a navigation aid. The basic technique remains in use to this day as one of the fundamental disciplines of signals intelligence, although typically incorporated into a larger suite of radio systems and radars instead of being a stand-alone system. Earlier systems used a mechanically rotated antenna or solenoid and an operator listening for peaks or nulls in the signal, which often took considerable time to determine the bearing on the order of a minute or more. Later systems used a set of antennas to receive the same signal in slightly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delhi
Delhi, officially the National Capital Territory (NCT) of Delhi, is a city and a union territory of India containing New Delhi, the capital of India. Straddling the Yamuna river, primarily its western or right bank, Delhi shares borders with the state of Uttar Pradesh in the east and with the state of Haryana in the remaining directions. The NCT covers an area of . According to the 2011 census, Delhi's city proper population was over 11 million, while the NCT's population was about 16.8 million. Delhi's urban agglomeration, which includes the satellite cities of Ghaziabad, Faridabad, Gurgaon and Noida in an area known as the National Capital Region (NCR), has an estimated population of over 28 million, making it the largest metropolitan area in India and the second-largest in the world (after Tokyo). The topography of the medieval fort Purana Qila on the banks of the river Yamuna matches the literary description of the citadel Indraprastha in the Sanskrit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Line
A landline (land line, land-line, main line, home phone, fixed-line, and wireline) is a telephone connection that uses metal wires or optical fiber telephone line for transmission, as distinguished from a mobile cellular network, which uses radio waves for signal transmission. Characteristics A corded landline telephone made by Siemens from c. 1997 Landline service is typically provided through the outside plant of a telephone company's central office, or wire center. The outside plant comprises tiers of cabling between distribution points in the exchange area, so that a single pair of copper wire, or an optical fiber, reaches each subscriber location, such as a home or office, at the network interface. Customer premises wiring extends from the network interface to the location of one or more telephones inside the premises. The telephone connected to a landline can be hard-wired or cordless and typically refers to the operation of wireless devices or systems in fixed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
